Published in Cambridge in 1864, H. A. J. Munro's two-volume critical edition of the Roman poet Lucretius' De Rerum Natura ('On the Nature of the Universe'), represents one of the finest contributions to classical scholarship of the nineteenth century. Lucretius' didactic poem, written in hexameters, is divided into six books and explains Epicurean cosmology. Munro's edition was conceived in response to that of the German philologist Karl Lachmann, who had published an edition of Lucretius in 1850. Munro began working on Lucretius in 1849 at which time he collated a range of manuscripts from European libraries. His first edition of the poem appeared in 1860. This revised edition followed in 1864 complete with an introduction, translation, and commentary. Volume 2 contains Munro's explanatory notes and the index.